Back when she was the star of her high-school drama club, the philosopher
Martha Nussbaum wasn't interested in playing Emily in "Our Town." Her favorite
role was Robespierre – in a five-act, French-language production she wrote
herself. Decades later, she still speaks fondly of the meandering walks she
would take around the affluent Philadelphia suburb of Bryn Mawr, dreaming of the
sacrifices the Frenchman made to advance his ideals. "I was fascinated by his
dilemma of wanting liberty for everyone, but having to figure out what to do
with individuals who won't go along with your plan," she recalled recently. "I
still think about it all the time." Nussbaum also remembered the fun she had
playing Joan of Arc, entranced as she was by the question of "how far to
sacrifice friendship and personal loyalty to an abstract cause." Although
Nussbaum eventually traded the stage for the academy, she still takes these
early inspirations to heart. Synthesizing the passion of the revolutionary with
the zeal of the self-sacrificing saint, she has become, at 52, the most
prominent female philosopher in America.

In addition to producing a steady stream of books and articles from her
perches at Harvard, Brown and now at the University of Chicago, she has
cultivated a distinctive, even glamorous, public presence. Nussbaum has
discussed Greek tragedy with Bill Moyers on PBS, presented Plato on the
Discovery Channel and been photographed by Annie Leibovitz for her new book,
"Women." More important, as a regular contributor to The New York Review of
Books and The New Republic, Nussbaum's essays have become required reading for
those with a taste for intellectual combat. Prized for her writing's acerbic
bite, she first attracted notice in 1987 with a devastating attack on Allan
Bloom's conservative diatribe "The Closing of the American Mind." Writing in The
New York Review of Books, she denounced his proposal that universities dedicate
themselves solely to educating the elite and savaged what she saw as Bloom's
distorted reading of Greek philosophy. "How good a philosopher, then, is Allan
Bloom?" she concluded. "We are given no reason to think him one at all."

Earlier this year, Nussbaum took aim at Judith Butler, the radical feminist
philosopher who has attained cultlike status (through dense monographs like
"Gender Trouble") for arguing, among other things, that society is built on
artificial gender norms that can best be undermined with "subversive" symbolic
behavior, like cross-dressing. Appearing in The New Republic, Nussbaum's
8,600-word essay, "The Professor of Parody," castigated Butler for proffering a
"self-involved" feminism that encouraged women to disengage from real-world
problems – like inferior wages or sexual harassment – and retreat to
theory. "For Butler," she wrote, "the act of subversion is so riveting, so sexy,
that it is a bad dream to think that the world will actually get better." By
abdicating the fight against injustice in favor of "hip defeatism," Butler,
Nussbaum concluded darkly, "collaborates with evil."

The review received a visceral response within the academy and beyond.
Butler's defenders branded it an ad feminam attack on an innovative thinker
whose reputation was surpassing Nussbaum's own. "It was a crassly opportunistic
act," said Joan Scott, a historian at the Institute for Advanced Study in
Princeton. Others welcomed Nussbaum's blow against the hermetic politics of
postmodernism. "The piece was a skillful and long-overdue shredding," said Katha
Pollitt, the feminist writer.

Although it would be hard to find two more ideologically dissimilar thinkers
than Bloom and Butler, according to Nussbaum's withering judgment they were
guilty of a common crime: both were mandarin philosophers who refused to use
their theories to help wage the battle for freedom, justice and equality. While
Bloom was at least openly skeptical about philosophy's connection to democracy
(he disparaged those who dared to seek practical advice from his beloved Greek
texts), Butler drew Nussbaum's ire because she claimed to be using philosophy to
address political issues even as she manipulated poststructuralist theory to
sidestep them. "I thought of the Butler and Bloom reviews as acts of public
service," she said. "But a lot of my impatience with their work grew out of my
repudiation of my own aristocratic upbringing. I don't like anything that sets
itself up as an in-group or an elite, whether it is the Bloomsbury group or
Derrida."

The debate over whether philosophy should play a mandarin or public role has
been a contentious one throughout American intellectual history. In the hands
of thinkers like Sidney Hook and John Dewey, philosophy turned its attention
"from the problems of philosophers toward the problems of men," as Dewey wrote
in "Reconstruction in Philosophy" (1920). After the Second World War, the
mainstream of American philosophy became reclusively "analytic," orienting
itself around the study of logic, mathematics and the philosophy of science,
while maintaining only a tenuous connection to the world at large. With John
Rawls's "A Theory of Justice" (1971), academic philosophy initiated a wary
rapprochement with its more socially engaged past, using the analytic idiom to
address age-old questions of justice. Nussbaum's work has played an important
part in this revival, as she has extended Rawls's liberal insights to examine
questions of gender, race and international development. She insists that
philosophy be rigorous and, above all, useful. Whereas Ludwig Wittgenstein once
compared philosophers to garbage men sweeping the mind clean of wrongheaded
concepts, Nussbaum believes they should be "lawyers for humanity" – a phrase
she borrows from Seneca, her favorite Stoic thinker. Part wonk, part sage,
Nussbaum is determined to make philosophy relevant to the modern world.

Given her rhetorical ferocity, I was surprised to find that Nussbaum was so
soft-spoken when we met in her airy apartment in the Hyde Park neighborhood of
Chicago. Dressed simply in a white T-shirt and black spandex leggings, she was
tall and striking, with a square jaw and wavy, shoulder-length blond hair.
Although she casually curled up on her living-room sofa, once we begin to talk
it became apparent that there was little soft about her. She answered every
question exhaustively, with a steely precision that let you practically see the
footnotes hovering in the air. Her hair was still damp from a grueling Sunday
routine: a 12-mile run along Lake Michigan followed by weight-lifting, intended
as preparation for a fall marathon. (Because she "detests earphones," she later
told me, she runs to a mental soundtrack: fully memorized extracts from "The
Marriage of Figaro.")

Nussbaum taught at Harvard and Brown for 20 years before coming to the
University of Chicago in 1995, where she has appointments in the law and
divinity schools, as well as in the departments of philosophy, classics and
Southern Asian studies. Her multiple affiliations attest to a breadth of
intellectual interest that is rare in a world of academic specialists. While
most scholars spend entire careers studying a particular era or thinker,
Nussbaum – in books like "The Fragility of Goodness," "For Love of Country" and
this year's "Sex and Social Justice" – moves easily from Aristotle to
international development, from Dickens to contemporary feminism.

When I asked why she reacted so strongly to Butler's work, she furrowed her
brow, looked down and spoke with the hushed, somber tone one might employ in
addressing a grave threat to national security. "Butler is like the Pied Piper
leading all the children away!" she told me. "If all these wonderful people drop
out of politics, then there are that many fewer people left to fight against
evil."

Such unabashed moralism is rarely heard from philosophers these days. "Martha
is unashamedly interested in goodness, which she writes about with such shocking
earnestness," explained her friend Leon Wieseltier, the literary editor of the
New Republic. "For her, philosophy is nothing less than an intellectual tool for
the improvement of mankind."

But Nussbaum's high-stakes rhetoric can irritate her peers. "It's zany," said
the literary critic Stanley Fish of Nussbaum's desire to make philosophy
helpful. "In the end, all philosophy equips you to do is more philosophy – it
doesn't make you better at any other area of public life." The philosopher
Richard Rorty was also dubious about her "impatient and dismissive" attacks on
fellow thinkers. "Her tone sometimes suggests that to differ from her is to
imperil the social bond," he said. Others attributed the hostility toward
Nussbaum to jealousy. "There are a lot of shriveled souls in the academic
world," said G.W. Bowersock, a historian at the Institute for Advanced Study,
"and they feel intimidated by Martha because she is able to do so much so well."

With Nussbaum's concern for philosophy's nuts-and-bolts utility, it is not
surprising that her strongest connection at Chicago is to the university's law
school – a contentious institution that has produced some of the most brilliant
legal theorists and judges in the country. At Chicago, theory is never far from
practice. Supreme Court Justice Antonin Scalia taught here; Federal Judge
Richard Posner (with whom Nussbaum taught a course on the French philosopher
Michel Foucault) founded the influential "law and economics" movement here.
Another prominent presence is the legal theorist Catharine MacKinnon, who
drafted some of the nation's strongest antipornography laws.

Nussbaum believes that one of the most effective ways she can change public
life is through her teaching at the law school. "Many of my students will go off
to be clerks and eventually judges and even legislators," she said. "Right now I
have three colleagues who are federal judges – and when I sit down and talk
with them, I hope I can change their views on some things, too."

Nussbaum's work as a "lawyer for humanity" comes primarily out of the liberal
political tradition, one that extends from John Stuart Mill to John Rawls. This
tradition emphasizes the equal worth of individuals and the inviolable freedom
to choose your path in life – regardless of gender, class, sexual orientation,
race or nationality. While this perspective may seem common-sensical to
outsiders, the insistence with which she applies her "universal" philosophy rubs
against an academic establishment wary of making cross-cultural judgments.

In 1986 Nussbaum was invited by the economist Amartya Sen (the 1998 Nobel
laureate with whom she was then romantically involved) to work with the United
Nations World Institute for Development Economics Research. Their aim was to
find alternatives to the dominant theories of international development: one,
the economist's view that a country's G.N.P. is the only reliable measure of
social, economic and political progress; two, the relativist position that
Westerners must refrain from judging foreign cultures.

To counter such positions, Nussbaum and Sen promoted the "capabilities
approach" to development, enumerating a universal set of values – the right to
life, bodily health and integrity; the right to participate in political
affairs; the right to hold property – that could be used to judge the quality
of life in any society. Unlike G.N.P. per capita's focus on opulence, wrote
Nussbaum in "Sex and Social Justice," the capabilities approach "asks about the
distribution of resources and opportunities. . . . It strongly invites a
scrutiny of cultural tradition as one of the primary sources of such unequal
abilities." For example, a wealthy Indian woman might have less "capability"
than a poor Swedish woman – because of the sexist society she lives in.

As part of her research, Nussbaum made frequent trips to India to study the
problems of poor women there. She advised programs aimed at increasing female
literacy in India and the prosecution of domestic violence there. Nussbaum has
little patience with those who accuse her of foisting "foreign" values on other
cultures. "It is better to risk being consigned by critics to the 'hell'
reserved for alleged Westernizers and imperialists," she wrote in "Sex and
Social Justice," "than to stand around in the vestibule waiting for a time when
everyone will like what we are going to say."

Nussbaum's rights-based universalism also undergirded her arguments for
equality for homosexuals. In 1993, she was asked to be a prosecution witness in
Romer v. Evans; the case challenged a Colorado amendment that sought to overturn
local laws protecting homosexuals from discrimination. In testifying, she
discovered that the career of the politically engaged philosopher can be fraught
with peril. Having never set foot inside a courtroom, the "lawyer for humanity"
was unprepared for how little a hostile cross-examination resembled the
free-ranging inquiry of the seminar. On the stand, Nussbaum cited classical
texts to argue that there were no ancient precedents for denying homosexuals
equality. "Plato's dialogues contain several extremely moving celebrations of
male-male love," she explained, "and judge this form of love to be, on the
whole, superior to male-female love because of its potential for spirituality
and friendship." Her testimony was attacked by several conservative scholars who
accused her of warping Plato's words. Nussbaum and her critics traded angry
accusations of libel and perjury – revolving around the interpretation of one
notoriously difficult Platonic dialogue – before the law was finally ruled
unconstitutional by the Supreme Court. When I asked whether she thinks her
scholarly reputation was tarnished by all the mudslinging, Nussbaum handed me
the 136-page law-review article she published on the case. It bristled with
dozens of pink Post-its. "If you read this you will see that my arguments were
all good and quite correct," she said curtly.

Nussbaum's "aristocratic" lineage derives from her mother's family, which
traces its roots back to the Mayflower. Her father, George Craven, was a
conservative Southerner who became a prosperous lawyer in the trusts and estates
division of a large Philadelphia firm. Young Martha rebelled from the start.
Much to her father's chagrin, she became involved in civil rights activism then
swirling around Bryn Mawr. One day, she invited a black girl over to play.
"Don't you ever bring a black person into our home again!" he scolded her.

Martha Craven fell in love with the theater while at the Baldwin School in
Bryn Mawr, where she wrote her French pageant. She attended Wellesley for two
years before growing frustrated with college and joining a Michigan theater
company that performed Greek tragedies. She acted in Aristophanes' "The Birds"
and in the "Oresteia," which starred Bert Lahr and Ruby Dee. After a stint at
the New York University drama school, Martha realized she preferred studying
plays to performing them and switched to the classics department, where she
earned her B.A.

Martha's Protestant father was horrified by her decision at N.Y.U. to marry a
Jew named Alan Nussbaum, a linguist she met in a class on Greek prose
composition. But she was an eager convert. "I had an intense desire to join the
underdogs and to fight for justice in solidarity with them," she has written.
For Nussbaum, Judaism offered a sense of community lacking in her own
upbringing. "I read Martin Buber and understood that virtually every
relationship I had observed at Bryn Mawr had been an I-It relationship,
involving no genuine acknowledgment of humanity," she wrote. Her marriage to
Alan Nussbaum ended in 1987.

Although Nussbaum thrived as a classics graduate student at Harvard, she felt
embattled. When she became the first woman ever elected to the prestigious
Society of Fellows (which guarantees a student three years of financing), the
question of what to call her arose. "Someone suggested that since the masculine
for 'fellow' was 'hetairos,' I should be called a 'hetaira,' which I knew full
well did not mean 'fellowess,' but was in fact Greek for 'prostitute,"' she
says. "I didn't like Harvard. I disapproved of the classicists. They were
anti-Semites, racists and sexists and had a real thuggishness about them." The
birth of her daughter, Rachel, only made Nussbaum more determined to prove her
mettle in a male bastion. A photo of her in the maternity ward shows her
proudly holding a copy of Aristotle's "Politics."

In the late 60's, the study of classical literature was largely a
philological pursuit, and since Nussbaum was growing more interested in the
ideas of Plato and Aristotle, she started to take classes in Harvard's
philosophy department. Aside from being predominantly Jewish, the department was
also more open to interdisciplinary inquiry. She wrote her classics dissertation
on a treatise by Aristotle, but she also began writing articles on Henry James
and Proust that drew on the full range of her literary and philosophical
interests.

Unfortunately, the very intellectual breadth that became Nussbaum's signature
caused problems for her professionally. Although Harvard had originally
appointed her jointly to teach classics and philosophy in 1975, Nussbaum was
denied tenure by the classics department in 1982. The experience devastated her;
she even considered bringing a sexual discrimination suit. Instead, she moved to
Brown University, where she taught until she came to Chicago four years ago.

On my last day in Chicago, I sat in on a class Nussbaum was teaching on John
Rawls and political liberalism in one of the law school's horseshoe-shaped
seminar rooms. The day's discussion examined the status of the family in liberal
political philosophy. "What would it be like for the principles of justice to
apply within the family?" she asked. She and her students engaged in a lively
debate about the tension between the family and the state: Is the family a
voluntary private association or should it be regulated by government? Should a
child be able to choose his own education or religion?

In 65 brisk minutes, Nussbaum interrogated the usefulness of the idea of
"family" in contemporary America – probing with the intensity of a
legislator. "Perhaps we should drop the label of family altogether," she
proposed, "and instead ask about the various goals and capabilities that people
have in these kinds of associations." Would employing a looser notion of family
change the state's stand on issues such as gay adoption or immigration? "What
are the practical implications of my approach? I really want to know!" Her voice
rose, as some in the class chuckled at her earnestness.

Sitting in her book-strewn office after class, I asked Nussbaum whether she
didn't sometimes take philosophy too seriously. Weren't there cases in which
theory didn't have to benefit humanity in any concrete way? For me, much of the
joy of studying philosophy often derived precisely from the escape it offered
from the world. Didn't this more purely aesthetic conception of philosophy's
vocation deserve equal time?

Nussbaum would have none of it. "For any view you put forward," she said,
"the next question simply has to be, 'What would the world be like if this idea
were actually taken up?"' Arrogantly or not, her scholarly objective is not to
impress her peers or win tenure – but to influence future generations, "laying
a foundation" for a more just world. "It's what happens in the long haul that
really matters," Nussbaum said. "You just never know where or how your ideals
will be realized."